PROJECT SUMMARY Maternal hyperglycemia during pregnancy is a known risk factor for high birthweight, excessive newborn adiposity, and related pregnancy complications including cesarean delivery, shoulder dystocia and birth injury. Sequelae of elevated pregnancy glucose are not limited to the perinatal period. Mothers meeting criteria for gestational diabetes are more likely to develop long-term metabolic disorders including Type 2 diabetes. Maternal glucose also has an apparent sustained influence on fetal programming, with offspring of hyperglycemic mothers at higher risk of both excess adiposity and disordered glucose metabolism throughout childhood and into adolescence. While debate exists as to specific criteria that should be used for diagnosing gestational diabetes, it is the case that adverse maternal and offspring outcomes related to both anthropometrics and glucose metabolism, both at delivery and over a decade later, are associated with maternal glucose values across the continuum. Existing diagnostic criteria for gestational diabetes are based on measures of maternal glucose, typically at ~28 weeks' gestation. To more fully elucidate maternal glycemia and identify potential early indicators of gestational diabetes, Clinical Centers comprising the National Institute of Diabetes and Digestive and Kidney Diseases' Glycemic Profile of Pregnancy Consortium will be charged with designing a multicenter observational study of pregnant mothers without pre-existing diabetes to richly characterize maternal glycemic profiles using sensor-based continuous glucose monitoring technology. The Northwestern University Biostatistics Research Center proposes to serve as a central leadership hub for the Glycemic Profile of Pregnancy Consortium, coordinating all data-related and operational activities using cutting-edge resources for study design, planning and conduct, ongoing data monitoring and statistical analysis.